Scientific Analysis of the Polychrome Paintings on the Stele Pavilion of Guandi Temple in Shanxi, China.

The stele pavilion at the Jiezhou Guandi Temple in Shanxi Province is a significant Qing-dynasty architectural structure within one of China's most renowned temple complexes dedicated to Guan Yu. However, its polychrome paintings have suffered severe deterioration due to prolonged weathering, and the composition, technological characteristics, and historical alterations of these paintings remain poorly understood. In this study, six polychrome pigment samples and one red oil-coating sample collected from different structural parts of the pavilion were systematically analyzed using laser Raman spectroscopy, scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, and pyrolysis-gas chromatography/mass spectrometry. The results show that the pigment layers primarily consist of mineral pigments including iron red, cinnabar, red lead, iron yellow, lavendulan, carbon black, and ultramarine, together with the organic pigment indigo. The oil coatings and polychrome paintings were restored in different periods. The initial oil coating, applied directly to the wood surface, has completely fallen off, whereas the later reapplication employed a single-layer ash ground with calcite aggregate and a binder of heat-bodied tung oil and rosin, indicating a simplified formula. The paint ground layer, dominated by kaolinite, contains pig blood, drying oil, and rosin, reflecting continuity with the Shanxi blood-based ground preparation tradition. These findings provide essential material evidence for conservation and offer a valuable case study for the technological history of Qing-dynasty regional architectural paintings in Shanxi.